6.2.1

This patch release fixes barcode background colors and sizing in generated PDFs after the 6.2.0 switch to vector barcodes, and cleans up install warnings in the website and playground.

## Fixes

- **Barcode background color:** `backgroundColor` now fills the whole schema box in both generated PDFs and the UI preview. In 6.2.0 the background was drawn only behind the barcode's content area. Rotation, opacity, and `colorType: 'cmyk'` apply to the background the same way as to the barcode. (#1632)
- **Barcode sizing:** Barcodes are stretched to fill their schema box again, as they were through 6.1.13 and as the UI preview shows them. 6.2.0 kept the barcode's own aspect ratio and left empty margins. (#1632)
- **Barcode color values:** Hex colors without `#` (for example `ffffff`) work again for barcode backgrounds instead of failing PDF generation. Colors with an alpha channel are honored, so `#00000000` draws no background and partial alpha draws a lighter one. (#1632)

## Dependencies and tooling

- **Website and playground installs:** `npm i` in `website/` and `playground/` no longer prints engine or install-script warnings, and the playground audit is clean. A root `.nvmrc` now pins Node 24 to match CI. (#1633)
- One moderate advisory remains in the website's development server, coming from `uuid` via `sockjs` (used by `webpack-dev-server` in Docusaurus). `sockjs` only uses `uuid` v4, which is not affected. It will go away when Docusaurus moves to `webpack-dev-server` 6. It does not affect the published site or the `@pdfme/*` packages. (#1633)

## Upgrade notes

- **Barcodes in non-square boxes look different from 6.2.0.** They now fill the box edge to edge, matching 6.1.13 and the Designer preview. For example, a QR code placed in a wide box is stretched horizontally. If you want an undistorted QR code, give it a square box. (#1632)